486 research outputs found

    Origin of Spin Incommensurability in Hole-doped S=1 Y2xCaxBaNiO5\rm Y_{2-x}Ca_x Ba Ni O_5 Chains

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    Spin incommensurability has been recently experimentally discovered in the hole-doped Ni-oxide chain compound Y2xCaxBaNiO5\rm Y_{2-x}Ca_x Ba Ni O_5 (G. Xu {\it al.}, Science {\bf 289}, 419 (2000)). Here a two orbital model for this material is studied using computational techniques. Spin IC is observed in a wide range of densities and couplings. The phenomenon originates in antiferromagnetic correlations ``across holes'' dynamically generated to improve hole movement, as it occurs in the one-dimensional Hubbard model and in recent studies of the two-dimensional extended t-J model. The close proximity of ferromagnetic and phase-separated states in parameter space are also discussed.Comment: RevTex, 4 pages, 4 figures (eps

    Bη(η)K(π)B \to \eta(\eta') K(\pi) in the Standard Model with Flavor Symmetry

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    The observed branching ratios for BKηB\to K \eta' decays are much larger than factorization predictions in the Standard Model (SM). Many proposals have been made to reconcile the data and theoretical predictions. In this paper we study these decays within the SM using flavor U(3) symmetry. If small annihilation amplitudes are neglected, one needs 11 hadronic parameters to describe BPPB\to PP decays where PP can be one of the π\pi, KK, η\eta and η\eta' nonet mesons. We find that existing data are consistent with SM with flavor U(3) symmetry. We also predict several measurable branching ratios and CP asymmetries for BK(π)η(η)B \to K (\pi) \eta(\eta'), η(η)η(η)\eta(\eta')\eta(\eta') decays. Near future experiments can provide important tests for the Standard Model with flavor U(3) symmetry.Comment: 13 pages, 4 table

    Targeting sustainable competitiveness in Croatia by implementation of “20 Keys” methodology

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    Throughout the current wave of regulatory reforms, several theoretical models have been proposed that call for the emergence of instruments of self-regulation under some form of state supervision as part of the demand to improve product development performances aligned with awareness of environmental needs, to help with meeting regulation and to reduce the risk of production nonconformance. “20 Keys” is one example of a mass application of a methodology for raising sustainable development and holistic approach to competitiveness in new EU member the Republic of Croatia, and therefore, the aim of this study is to observe the results of the methodology application in Croatian companies. 20 Keys is a methodology that brings an integrated set of tools aimed at increasing overall productive efficiency and quality level with simultaneous reduction of costs. As it was shown in this paper, implementation success is coincident with senior management’s active role in setting the main goals for implementation, assuring that suitable methods and tools are used, allocating resources appropriately and enabling communication within the company

    Lactate signalling regulates fungal β-glucan masking and immune evasion

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    AJPB: This work was supported by the European Research Council (STRIFE, ERC- 2009-AdG-249793), The UK Medical Research Council (MR/M026663/1), the UK Biotechnology and Biological Research Council (BB/K017365/1), the Wellcome Trust (080088; 097377). ERB: This work was supported by the UK Biotechnology and Biological Research Council (BB/M014525/1). GMA: Supported by the CNPq-Brazil (Science without Borders fellowship 202976/2014-9). GDB: Wellcome Trust (102705). CAM: This work was supported by the UK Medical Research Council (G0400284). DMM: This work was supported by UK National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC/K000306/1). NARG/JW: Wellcome Trust (086827, 075470,101873) and Wellcome Trust Strategic Award in Medical Mycology and Fungal Immunology (097377). ALL: This work was supported by the MRC Centre for Medical Mycology and the University of Aberdeen (MR/N006364/1).Peer reviewedPostprin

    Ferromagnetism in the one-dimensional Hubbard model with orbital degeneracy: From low to high electron density

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    We studied ferromagnetism in the one-dimensional Hubbard model with doubly degenerate atomic orbitals by means of the density-matrix renormalization-group method and obtained the ground-state phase diagrams. It was found that ferromagnetism is stable from low to high (0< n < 1.75) electron density when the interactions are sufficiently strong. Quasi-long-range order of triplet superconductivity coexists with the ferromagnetic order for a strong Hund coupling region, where the inter-orbital interaction U'-J is attractive. At quarter-filling (n=1), the insulating ferromagnetic state appears accompanying orbital quasi-long-range order. For low densities (n<1), ferromagnetism occurs owing to the ferromagnetic exchange interaction caused by virtual hoppings of electrons, the same as in the quarter-filled system. This comes from separation of the charge and spin-orbital degrees of freedom in the strong coupling limit. This ferromagnetism is fragile against variation of band structure. For high densities (n>1), the phase diagram of the ferromagnetic phase is similar to that obtained in infinite dimensions. In this case, the double exchange mechanism is operative to stabilize the ferromagnetic order and this long-range order is robust against variation of the band-dispersion. A partially polarized state appears in the density region 1.68<n<1.75 and phase separation occurs for n just below the half-filling (n=2).Comment: 16 pages, 16 figures, final version, references adde

    Evaluation of alternative techniques to determine pork carcass value

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    Three techniques for estimating the value of pork carcasses were evaluated: an optical probe, a real-time ultrasound scanner, and an electromagnetic scanner (EMSCAN). The ability of these techniques to predict carcass value was compared to the predictive ability of actual measures of backfat depth and longissimus muscle area taken with a ruler and a dot grid. Results indicated the EMSCAN model was the best predictor of carcass value. However, the optical probe, ultrasound, and the ruler/dot grid all provided information not contained in the EMSCAN model. The choice among ultrasound, the optical probe, and the ruler/dot grid depends on how the carcass will be used. There is no significant difference between ultrasound and the ruler/dot grid or the optical probe and the ruler/dot grid if the carcass is to be marketed in wholesale primal form, but the ruler/dot grid is superior if the ham and loin are to be sold as lean, boneless products. A model combining the EMSCAN and optical probe readings provided more accurate value predictions than either technique alone. A carcass value matrix for use in pricing pork carcasses was developed using readings from the optical probe. Carcass use has a substantial impact on value differences between fat and lean pigs.Not peer reviewedAgricultural Economic

    Combined KRAS-MAPK pathway inhibitors and HER2-directed drug conjugate is efficacious in pancreatic cancer

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    Targeting the mitogen-activated protein kinase (MAPK) cascade in pancreatic ductal adenocarcinoma (PDAC) remains clinically unsuccessful. We aim to develop a MAPK inhibitor-based therapeutic combination with strong preclinical efficacy. Utilizing a reverse-phase protein array, we observe rapid phospho-activation of human epidermal growth factor receptor 2 (HER2) in PDAC cells upon pharmacological MAPK inhibition. Mechanistically, MAPK inhibitors lead to swift proteasomal degradation of dual-specificity phosphatase 6 (DUSP6). The carboxy terminus of HER2, containing a TEY motif also present in extracellular signal-regulated kinase 1/2 (ERK1/2), facilitates binding with DUSP6, enhancing its phosphatase activity to dephosphorylate HER2. In the presence of MAPK inhibitors, DUSP6 dissociates from the protective effect of the RING E3 ligase tripartite motif containing 21, resulting in its degradation. In PDAC patient-derived xenograft (PDX) models, combining ERK and HER inhibitors slows tumour growth and requires cytotoxic chemotherapy to achieve tumour regression. Alternatively, MAPK inhibitors with trastuzumab deruxtecan, an anti-HER2 antibody conjugated with cytotoxic chemotherapy, lead to sustained tumour regression in most tested PDXs without causing noticeable toxicity. Additionally, KRAS inhibitors also activate HER2, supporting testing the combination of KRAS inhibitors and trastuzumab deruxtecan in PDAC. This study identifies a rational and promising therapeutic combination for clinical testing in PDAC patients

    Analysis of an exhaustive search algorithm in random graphs and the n^{c\log n} -asymptotics

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    We analyze the cost used by a naive exhaustive search algorithm for finding a maximum independent set in random graphs under the usual G_{n,p} -model where each possible edge appears independently with the same probability p. The expected cost turns out to be of the less common asymptotic order n^{c\log n}, which we explore from several different perspectives. Also we collect many instances where such an order appears, from algorithmics to analysis, from probability to algebra. The limiting distribution of the cost required by the algorithm under a purely idealized random model is proved to be normal. The approach we develop is of some generality and is amenable for other graph algorithms.Comment: 35 page

    Clinical and molecular characterization of a transmitted reciprocal translocation t(1;12)(p32.1;q21.3) in a family co-segregating with mental retardation, language delay, and microcephaly

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    <p>Abstract</p> <p>Background</p> <p>Chromosome translocation associated with neurodevelopmental disorders provides an opportunity to identify new disease-associated genes and gain new insight into their function. During chromosome analysis, we identified a reciprocal translocation between chromosomes 1p and 12q, t(1; 12)(p32.1; q21.3), co-segregating with microcephaly, language delay, and severe psychomotor retardation in a mother and her two affected boys.</p> <p>Methods</p> <p>Fluorescence in situ hybridization (FISH), long-range PCR, and direct sequencing were used to map the breakpoints on chromosomes 1p and 12q. A reporter gene assay was conducted in human neuroblastoma (SKNSH) and Chinese hamster ovary (CHO) cell lines to assess the functional implication of the fusion sequences between chromosomes 12 and 1.</p> <p>Results</p> <p>We determined both breakpoints at the nucleotide level. Neither breakpoint disrupted any known gene directly. The breakpoint on chromosome 1p was located amid a gene-poor region of ~ 1.1 Mb, while the breakpoint on chromosome 12q was located ~ 3.4 kb downstream of the ALX1 gene, a homeobox gene. In the reporter gene assay, we discovered that the fusion sequences construct between chromosomes 12 and 1 had a ~ 1.5 to 2-fold increased reporter gene activity compared with the corresponding normal chromosome 12 sequences construct.</p> <p>Conclusion</p> <p>Our findings imply that the translocation may enhance the expression of the ALX1 gene via the position effect and result in the clinical symptoms of this family. Our findings may also expand the clinical phenotype spectrum of ALX1-related human diseases as loss of the ALX1 function was recently reported to result in abnormal craniofacial development.</p
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